T=5bleft(-6b+7right)-(7b^2+5b-1)*9 eching

$$T = 5b \left( -6b+7 \right) -(7 { b }^{ 2 } +5b-1) \times 9$$

T uchun yechish

$$T=9-10b-93b^{2}$$

Yechim qadamlari

5b ga -6b+7 ni ko'paytirish orqali distributiv xususiyatdan foydalanish.

$$T=-30b^{2}+35b-\left(7b^{2}+5b-1\right)\times 9$$

7b^{2}+5b-1 ga 9 ni ko'paytirish orqali distributiv xususiyatdan foydalanish.

$$T=-30b^{2}+35b-\left(63b^{2}+45b-9\right)$$

63b^{2}+45b-9 teskarisini topish uchun har birining teskarisini toping.

$$T=-30b^{2}+35b-63b^{2}-45b+9$$

-93b^{2} ni olish uchun -30b^{2} va -63b^{2} ni birlashtirish.

$$T=-93b^{2}+35b-45b+9$$

-10b ni olish uchun 35b va -45b ni birlashtirish.

$$T=-93b^{2}-10b+9$$

b uchun yechish

$$b=\frac{\sqrt{862-93T}-5}{93}$$

$$b=\frac{-\sqrt{862-93T}-5}{93}\text{, }T\leq \frac{862}{93}$$